Example 1:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 4 Example 1 Is (1, 3) a solution to the system? Just plug the coordinates into the system. YES

Example 2:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 5 Example 2 Is (1, –3) a solution to the system? Just plug the coordinates into the system. NO

Steps when graphing:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 6 Graph both equations (y=mx+b) Determine what the intersecting point is and write as a coordinate point Check your point in both equations Steps when graphing

Example 3:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 7 Example 3 Graph these equations and determine the intersection points for this system 1. 2. Start with equation #1 and solve for y:

Example 3:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 8 Example 3 Graph these equations and determine the intersection points for this system 1. 2. Then take equation #2 and solve for y:

Example 3:

Example 3:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 10 Example 3 Check to see if (4, 4) is the accurate solution to the system…

Using Graphing Calculator:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 11 Using Graphing Calculator Graph these equations and determine the intersection points for this system Must be in Y= Form

Example 4:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 15 Example 4 Graph these equations and classify this system The system is consistent and dependent with infinitely many solutions.

Example 5:

10/23/2012 10:12:25 PM 3-1: Solving Linear Equations through Graphing and Tables 18 Example 5 Ravi is comparing the costs of long-distance calling cards. To use the Sprint card it costs 8 cents to connect and then 0.5 cents per minute. The MCI card costs 5 cents to connect and then 0.8 cents per minute to talk. For what number of minutes would calls made with each card cost the same amount?